eBURST analysis and minimum Spanning Networks of 7th pandemic V. cholerae isolates based on MLVA. A) MLVA using 6 VNTR loci and B) MLVA using 4 VNTR loci from chromosome I. Each circle represents a unique MLVA profile, with the isolate number/s belonging to the MLVA type within the circles. The colour of each circle denotes the group to which each isolate belongs according to Single Nucleotide Polymorphism (SNP) typing  (see Figure 2). Singletons are arranged by SNP groups while members of clonal complexes are connected using minimum spanning network. Thick connecting lines represent differences of one repeat unit with red lines indicating connections chosen in the minimum spanning tree shown in Additional file 1 Figure S 1 based on priority rules described in the text and thin solid lines represent one locus difference with more than one repeat difference. The size of each circle reflects the number of isolates within the circle.